Recommended Processing model for NOSCRIPT element

Hi,

    Kindly go through the "Recommended Processing model for
    NOSCRIPT Element".

    Give your comments/feedback on this..

    Thanks

Regards

Seshadri



Recommended Processing Model for NOSCRIPT Element
=================================================

This is to describe a processing model for NOSCRIPT elements in
order to bring the real significance of NOSCRIPT Element.

The significance of NOSCRIPT element is conceptually often 
assumed
to provide an alternative content when a script can not be
executed.  The existing processing model describes the 
processing
of NOSCRIPT element under various circumstances.  However it has
been realised that the real significance of NOSCRIPT element has
not been achieved yet, due to some ambiguities in the current
processing model with respect to logical/conceptual aspects.


Some of the ambiguities have been described below:



HTML 4.01 Definition:



  The content of a NOSCRIPT element should only be rendered by a
script-aware user agent in the following case:


    * The user agent doesn't support a scripting language 
invoked
by a SCRIPT element earlier in the document.



Example 1:



    <script type="text/javascript">
     ....

    </script>

    <noscript>

     JavaScript is not supported!!!

    </noscript>

    <script type="text/vbscript">

     ....

    </script>

    <noscript>

     Vbscript is not supported!!!

    </noscript>


In the above example, assume that the vbscript is supported by 
the
user agent, and the javascript is not.  The natural expectation
would be like "The user agent should process the first NOSCRIPT
element alone, as the javascript is not supported by the
script-aware user agent."  But the current processing model 
allows
the user agent to process all the NOSCRIPT elements irrespective
of the place where the NOSCRIPT elements have been specified.  
As
a result of this, the contents

  Javascript is not supported!!!

  and

  Vbscript is not supported!!!

are displayed, when one of the scripting language is not
supported.

This creates some sort of ambiguities interms of
logical/conceptual aspects, also, not giving a real significance
for NOSCRIPT element.  The processing model would have been much
better, if it allows only those NOSCRIPT elements that 
corresponds
to the SCRIPT element whose content type is not supported.

It is recommended that following guidelines can be adopted by
W3C.

1. The user agent MUST process all NOSCRIPT elements, when the
user agent does not support scripts or is configured not to
evaluate script.

2. If the user agent supports scripts and is configured to
evaluate script.

       * If the user agent encounters a SCRIPT element, whose
content type is not supported by the user agent, then it

           should process all the subsequent NOSCRIPT elements
till it encounters the next SCRIPT element or end of the

           document, whichever comes first.



These suggested guidelines would certainly improve the real
significance of NOSCRIPT element.

Received on Thursday, 30 January 2003 00:39:21 UTC